The effect of nitro-L-arginine [(NLA), inhibitor of nitric oxide synthase (NOS) or L-arginine [(LA), precursor of nitric oxide (NO)] on cerebral blood flow (CBF), blood pressure (BP), and dopamine (DA) metabolism was investigated in the gerbil model of global ischemia. Inhibition of NOS by NLA in contrast to LA delayed the initial recovery of CBF and altered DA metabolism in brain ischemia-reperfusion. The data suggest that nitric oxide is involved in postischemic CBF recovery and NLA-induced CBF reduction in modulating DA metabolism.